The present invention relates generally to blowers, and more particularly to a blower-operated airknife for directing an elongated narrow width curtain of air.
Blower operated airknives are known for directing elongated air curtains for various purposes such as, for example, drying, cooling, or cleaning items conveyed transversely through the air curtain. Such airknives typically have a narrow elongated slit-like discharge orifice and are supplied with a low-pressure air that is channeled through the discharge orifice in a downwardly or outwardly directed curtain of air. From an economical standpoint, it is desirable to use relatively low-pressure blowers with such air knives, such as blowers that operate at pressures on the order of 5 psi. A problem with such low air pressure operated airknives is that the volume and velocity of the discharging air can be limited, which in turn can limit the effectiveness of the air curtain, including its effective transverse width, i.e. the width of the curtain in the direction of travel of items conveyed through the air curtain.
It is an object of the present invention to provide a blower-operated airknife that is adapted for more efficient operation.
Another object is to provide a blower operated airknife as characterized above that is effective for producing a significantly greater air flow for a given inlet air pressure. A related object is to provide such an airknife that is adapted to produce a higher volume and/or velocity air curtain without increasing the size or operating pressure of the associated blower.
A further object is to provide a low pressure blower operated airknife of the above kind that is adapted for producing a more effective, higher volume and/or velocity, air curtain with a greater width in the direction of travel of items passing through the air curtain.
Still another object is to provide an airknife of the foregoing type which is adapted for the low-pressure direction and application of air-laden particles, and particularly air curtains which carry and deposit pre-atomized liquid particles.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: